The relationship between fat-free mass index and pulmonary hyperinflation in COPD patients

Background and objective Reduced fat‐free mass (FFM), a common finding in chronic obstructive pulmonary disease (COPD), may indirectly impact peak exercise capacity through a greater level of pulmonary hyperinflation. We aimed to investigate if FFM index (FFM/squared height) impacts exercise induced dynamic hyperinflation in COPD patients. Methods Fifty‐four patients with moderate‐to‐very severe COPD performed a symptom limited incremental cardiopulmonary exercise tests with serial measurements of inspiratory capacity (IC). FFM was measured by whole‐body bioelectrical impedance. Results Patients were 66.7 ± 7.7 years old with mean forced expiratory volume in 1 s (FEV1) of 1.08 ± 0.41 L (42 ± 15% of predicted). Peak exercise IC was significantly (P